Using matrix norms to estimate the direction of arrival of planar waves on an ULA

SEAD method estimates the direction-of-arrival angles on an uniformly linear array based on the difference between the two largest singular values, what is called differential spectrum. Although it presented an outstanding performance, the ability to indicate the source positions was not elucidated yet. Inspired by the differential spectrum formulation we derived a total differential spectrum and found out that the matrix norm induced by the vector 2-norm of a modified spatial covariance matrix can be used to estimate the direction-of-arrival of multiple plane waves. Indeed we show that matrix norms are estimators and we propose their use instead of the singular value decomposition in SEAD-based methods. We present a general mathematical expression in order to explicit the operating principles of the proposed methods. Consequently, we were able to explain how the relation between the arriving and the search angles produces the larger peaks on the differential spectrum. To evaluate the important role played by matrix norms, a thousand experiments were carried out. They showed that the proposed approach proved to be as accurate as the previous SEAD-based methods, while providing a significant reduction on runtime. It also outperformed well-established methods like MODEX regarding the estimation error.     

Pigments and binders in “Madonna col Bambino e S. Giovannino” by Botticelli investigated by micro-Raman and GC/MS

During the restoration plan of the famous painting “Madonna col Bambino e S. Giovannino” by Sandro Botticelli, located in the Museo Civico of Piacenza (Italy), a study on painting materials was carried out. The pigments, the binders and the materials used for the application of ground and priming layers were studied using micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry (GC/MS), optical and electronic microscopies. Gypsum and anhydrite were found in the ground layer, while carbon black and lead white were used in the priming layers. The precious pigments of the artist's palette and the binders used (egg and animal glue) were determined.     

未来的主人翁：NBA年轻一代领袖档案

1984年乔丹领衔的黄金一代,开辟了90年代NBA众星捧月的大场面,马克利、奥拉朱旺、尤因、雷吉·米勒、超音速双怪以及犹他二老与篮球之神迈克尔·乔丹的轮番PK造就了美国职业篮球最辉煌的时代。1996年选秀大会又为联盟输送了科比·布莱恩特、阿伦·艾弗森、雷·阿伦这一批优质球星,加上1997年的邓肯和麦迪以及1995年的凯文·加内特,这一拨人是1998年乔丹退役之后NBA的中坚力量。     

一个无政府主义者的自然死亡

这个年代没有人会去深究上帝是否存在,也有人会不再认为他们读的圣经真的具有伟大的救赎之力能拯救世人脱离撒坦的阴暗。信仰在某种意义上。已经成为了一种纯粹供人们自我安慰的道德他律力量。所谓上帝的子民。在被消费主义日渐吞噬的现代社会浮沉之后,也不免会成为罪恶的祭品。     

Combined training,FNDC5/irisin levels and metabolic markers in obese men: A randomised controlled trial

The effects of training on FNDC5/irisin and its association with fitness and metabolic marker improvements induced by training have been poorly investigated in humans. Thus, the present study assessed the effects of combined training (CT) on FNDC5/irisin levels, metabolic markers and fitness adaptations in obese men. Middle-age obese men (age 49.13?±?5.75, body mass index (BMI) 30.86?±?1.63) were randomly distributed in the CT group (n?=?12) and control group (CG n?=?10). The CT consisted of strength followed by aerobic training, 3 times/week, for 24 weeks. Body composition, physical fitness, plasma FNDC5/irisin, biochemical markers and metabolic scores/index were evaluated. CT maintained FNDC5/irisin levels (µg/mL) (pre: 4.15?±?0.32, post: 4.21?±?0.32; p?=?.96) and improved body composition, metabolic and physical fitness markers. In the CG, decreased FNDC5/irisin (µg/mL) (pre: 4.36?±?0.23, post: 3.57?±?0.94; p?=?.01) and reduced strength (supine exercise/kg) (pre: 71?±?14.7, post: 60.1?±?14.05; p?<?.01) were observed, along with a trend to increase HOMA-IR (pre: 2.63?±?1.11, post: 3.14?±?1.27; p?=?.07) and other indicators of metabolic deterioration. An inverse correlation was found between the change (Δ%) in levels of FNDC5/irisin and Δ% glucose, Δ% total cholesterol, Δ% triglycerides and Δ% waist circumference, in addition to a positive relation with Δ% muscle strength. In conclusion, CT maintained FNDC5/irisin levels and provided metabolic and fitness benefits. The correlation between FNDC5/irisin changes and metabolic parameters, as well as the FNDC5/irisin reduction associated with fitness and metabolic worsening in the CG, suggests a relationship between FNDC5/irisin and a healthy metabolic status in humans.     

A case analysis of semantic technologies for R&D intermediation information management

It is evident that companies and research centres can find a myriad of instruments to fund their R&D (Research & Development) activities. Due to the dynamics of the information management in these circumstances there is a need for intermediary businesses intervention. Consequently, intermediary companies are thus involved in a complex process that needs to be managed and controlled. Within this scenario an Information Technology (IT) platform, named RDi-Advise, was developed by EgeoIT using semantic technologies to support R&D process decisions. This case analysis describes the development and implementation of the platform including the lessons learned during the activity period.     

The impact of funding on research collaboration: Evidence from a developing country

In this paper we evaluate the impact of research grants on the amount of collaboration among scientific researchers in Argentina. We find a positive and significant impact of funding on collaboration which is measured in terms of the number of co-authors for publications in peer-reviewed journals. Our identification strategy is based on comparing collaboration indicators for researchers with financially supported projects with those of a control group of researchers who submitted projects that were accepted in terms of quality, but not supported because of shortage of funds. We obtain consistent results by using different non-experimental techniques including difference-in-differences models combined with propensity score matching algorithms.     

Comparing Graphical and Verbal Representations of Measurement Error In Test Score Reports

Research has shown that many educators do not understand the terminology or displays used in test score reports and that measurement error is a particularly challenging concept. We investigated graphical and verbal methods of representing measurement error associated with individual student scores. We created four alternative score reports, each constituting an experimental condition, and randomly assigned them to research participants. We then compared comprehension and preferences across the four conditions. In our main study, we collected data from 148 teachers. For comparison, we studied 98 introductory psychology students. Although we did not detect statistically significant differences across conditions, we found that participants who reported greater comfort with statistics tended to have higher comprehension scores and tended to prefer more informative displays that included variable-width confidence bands for scores. Our data also yielded a wealth of information regarding existing misconceptions about measurement error and about score-reporting conventions.     

Acculturation and School Success: Understanding the Variability of Mexican American Youth Adaptation Across Urban and Suburban Contexts

The Urban Review - This article concentrates on the educational experiences of urban and suburban Mexican American youth, from recent immigrants to those that have been in the United States for...